Short delay fuse elements



Patented Jan. 6, 1948 UNITED STATES PATENT OFFICE I V 2,434,067 I SHORT DELAY FUSE ELEMENTS Joseph C. Frazer, Baltimore, and'Ow'en G. Bennett, Forest Hills, Pa., assignors to Catalyst Research Corporation, Pittsburgh, Pa., a

corporation of Maryland No Drawing. Application March 26, 1943,

Serial No. 480,600

' Black powder has been us'e'd largely in the fuse elements of hand grenades and related military devices' whose -functioning'depehds upon the setting "oif'of 'bursting-"or'propellant charges. In

our copending application Serial No. 469,978, filed December 24, 1942, we have disclosed a new class of fuse compositions iwhich 'minimize or avoid "the shortcomingsof' black powder fuses.

The fuse compositions disclosed in that application comprise an intimate mixture of finely divided metal and an oxidizing agent, suitably a chlorate, a perchlorate or a permanganate.

The fuse elements available heretofore, whether made from black powder from other compositions including those disclosed in our aforesaid copending application, are inadequate for certain express purposes which demand as an absolute criterion extraordinary rapidity of reaction, or combustion, of the fuse composition. That is, the rate of reaction of the previously known fuse compositions is too slow for some purposes, as where it is desirable that the charge of an explosive bullet be set oil in passing through some object which is traversed in a fraction of a second.

A major object of this invention is to provide fuse compositions which are particularly characterized by extremely and unusually great rapidity of reaction, and which are of simple composition, are made easily from readily available materials, are wholly safe to handle, and develop no gaseous reaction products.

A further object is to provide short delay fuse elements which function in very brief intervals of time even to the order of hundredths of a second.

Other objects will appear from the following description.

We have discovered, and it is upon this that our invention is in large part predicated, that mixtures of finely divided, or powdered, metallic nickel and elemental sulfur provide compositions which when ignited undergo extremely rapid reaction and are especially adapted for use as short delay fuse elements that function in much briefer periods of time than has been possible with the fuse compositions available prior to the present invention.

Both the nickel and the sulfur should be finely divided for the purposes of this invention, and generally speaking the greater the degree of subdivision the more rapid will be the reaction. We

4 Claims. (Cl. 521) have found that the most satisfactory results are to be had by preparing the nickel by the'process disclosed in our Patent No. 1,893,879, granted January 10, 1933, according to which mercur is evaporated from a nickel amalgam, most suitably by subjecting such an amalgam to distillation under high vacuumyto volatilize. all of the mercury. Nickel produced in thatmanner'is in the form of an exceedingly fine ,powderiwhich exhibits unusually ,high activity. However, it may be stabilized so that it can be handled freely in the air by passing carbon dioxide into contact with the metal subsequent to evaporation of the mercury and prior to contact to oxygen.

For most purposes we prefer to use stoichiometrical proportions of sulfur and nickel, based upon the production of nickel sulfide, but the relative proportions of the two ingredients may be varied from that relation although for most purposes it is preferred that if either constituent be in excess, it should be sulfur.

These compositions are prepared readily and simply by mixing the two constituents in any suitable device which will produce the necessary intimate mixture. No danger is involved in this operation. The composition may be used in powdered form for some purposes, but for other purposes and particularly to avoid objectionable segregation of one of the constituents it may be compressed to form adherent self-supporting bodies.

The time of reaction can be controlled to some extent by the particle size of the ingredients, but it may be retarded most readily by the additional use of some inert, inorganic diluent, of which a variety are available. We now prefer to use diatomaceous earth for this purpose.

As exemplifying the extremely rapid action of compositions provided by the invention, a mixture of stoichiometrical proportions of sulfur and nickel prepared by amalgam distillation, and diatomaceous earth was filled into a metallic tube inch long and of 0.02 inch internal diameter. The composition was set off with an ordinary percussion primer, and as nearly as could be determined with the timing means available, reaction was complete in less than 0.2 second. In comparison, fuse elements of the same size filled with black powder or with nickel-potassium perchlorate diatomaceous earth mixtures in accordance with our aforesaid application required 1.75 seconds for completion of reaction. The reaction time of the foregoing composition in accordance with the present invention was greater than is possible, due to the action of the diatomaceous earth, and from our experiences we believe that the reaction is so rapid that fuse elements adapted for use with, for example, explosive bullets can be provided which will cause the bullet to burst within about 0.03 second after coming into contact with an object.

The composition provided by the information can, if desired, be used in standard fuse constructions, such for example, as tubular members which contain a charge of the composition adapted to exert the desired action in a given interval of time. Generally speaking, such elements will be set oil by means of a percussion primer associated in known manner with the element.

The compositions provided bythis invention are characterized by a low heat of reaction, and accordingly despite the extraordinary rapidity of reaction they evolve a relatively small amount of heat which is, however, sufficient for many purposes.

According to the provisions of the patent statutes, we have explained the principle, mode of compounding and mode of operation of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. A high speed fuse composition comprising as essential active ingredients an intimate mixture of sulfur and finely divided nickel produced by distillation of mercury from a nickel amalgam, the composition reacting with extreme rapidity when ignited and producing only solid reaction products.

2. A composition according to claim 1 including also diatomaceous earth.

3. A high speed fuse composition consisting of an intimate mixture of sulfur, finely divided nickel produced by distillation of mercury from a nickel amalgam, and an inert diluent, the composition reacting with extreme rapidity when ignited and producing only solid reaction products.

4. A composition according to claim 3, said 

